Probably best not to have the tool in carry-on, even powered-off, and I'd understand if TSA didn't permit that (like they wouldn't let a chef carry-on their knives, another tool with very legitimate purposes).
The TSA also doesn't care, they don't look for, and don't remotely have the training to detect suspicious electronics. Even if they did the flipper looks very innocuous unless you know what it is. You can reliably get much more entertaining things onto airplanes without them batting an eye.
It’s like getting upset by a lock picking set except this isn’t even a lock picking set and more like a door knob diagnostic tool.
I am not excusing the behavior, but I also don't see arrest as an appropriate remedy.
This is in no way an endorsement of fucking around with one on an airplane, or even off an airplane when used without the consent of the target.
It's a dick move but banning the hardware doesn't do anything because you can port such simple hacks to any platform. It's the action that should be policed.
Someone on the plane I was on kept triggering it to do bluetooth attacks ('not your airpods') while I was trying to read (and have my earphones on connected via bluetooth so fuck me right?).
There's hacked firmware's you can install [0]. I understand that there are probably tons of other devices like this out there but this one was SO fucking popular and easily accessible.
I've already seen this thing abused and used in a super obnoxious way. Frankly I think you should be arrested for having it on in the passenger cabin of an airplane.
[0] https://github.com/DarkFlippers/unleashed-firmware